Quantum Information Science

Quantum processing machines can, in principle, seriously outperform some of our current information technologies. For instance, anyone possessing a computer capable of implementing a quantum factoring algorithm will gain virtual access to most secure communications as well as databases. Moreover, quantum entanglement can also be used to avoid any eavesdropping in communications. This has led to an intense effort to build quantum processors and quantum communication devices. However, in practice, processing information remains a challenging task. It is still not clear which physical system is most suitable for implementing quantum computation at large scales. In addition, one needs not only full control and the possibility for large-size scaling, but also to cope with errors and imperfections, as quantum systems are very susceptible to noise coming from their environment. Two groups in our Department develop theoretical work on these fronts. Leuenberger and his group study quantum bits made from optical semiconductor quantum dots while Mucciolo and his group explore the physical limits of quantum computation and communications and ways to mitigate the noise problem.